And malcolm s



UHUOO nLl'lmlnLiUL. unnnuua L. BURCH ET ,QL

SECRET SIGNALING SYSTEM ATTGRNM Patented Sept. l29, 1925.-

UNITED STATES.

assi-:,633

Irarea'r orifice.

LYNDEN 'UxtUl-I, OF BELLEVILLE, NEW JERSEY, AND .MLCTJIWI 3f..'.E-Alft-flll?, GES' `NEVI YORK, N. Y.

SECRET SIGNALNG SYSTEM.

Application med December ATo all 'w71 om t may concern.

Be it known that Wc,'LYNocN linnen and MALCoLM K, .lriunlrnnsn bothcitizens ot the United States, residing at Belleville, in the county ot'Essex and fiiatc ol Non' Jersoy, and New York city, in. the cminty Bronxand Stale of New York, respectively, have invented cert-.1in ncav anduseful lui-I prorcinei'its in Secret frliirnalinr Systems; and we dol'icreby declare the following to be a ilnll, clear, and exactdeyeription of the. iiirci'itif'm, snchV as will cnahle othersskille-,fl in the. art to which it a'gijijafi'lans to niake and use thesan-ic.

This inventioii relates io secret si/naling syst'enis such astelegrailili and telep ie tems', and is directed7 incre particularly,to. asysleni 'tor secret inl'crcoininnniration ha iwecn radio stations.

Systems tor acconiiplishing secret adio communication `by moans oiperiodic' were length changes at the transmitting station. haveheretofore been proposed, hut in each instance, so i'ar asoit has beenascorta-ined,

the arrangement has been such that IeitherA a comparatively simplereceiving,` apparatus V,winch could be readily constructed and open atedby anyoncskllled 1n the art was capable Aof defeating the purpose oit'the proposed" system; or the receiving 'apparatus was so coi'njplicaledas to render vit iinpracticable for t tuning.,4 u l t, i

VLccordinic'r, to the former type ol arral'igge4 designed tooperate .ontwo ware lengths alternately; and the receivine' statica was providedwith a. receiving' apparatus capable ofrespondingY to two Ware ,lengthssiniul tancously. Receiving apparatus ot that characteris very rosy toconstruct, and it is therefore' a simple matter for Would-,beeavesdroppers to defeat the, purpose of such a. system. The Second typearrangement referred to is merely an extension of the 'y first, anddiljl'ers therefrom only `in that a larger number ot Wave lengths weretrans mitted in'seriatim. Receiving apparatus of the latter characterwas designed robe rc sposive to all of the severaltransmitted Wavelengtlis concurrently. Receivinglapparatas of 'this character, where alarge man ber of wave lengths are employed, is extremely complexand'dillcnlt to adjust. In fact, it amounts practically to an aggroea-1922. Serial No. @Hi8-QS.

tion' ot receiving stat-ions equal in number to the nunihcr oi' Wave.lengths employed. For emniplc` if y six vfarc lengths were employedA` it'was necessary to provide re ceiving ai tmratus which was practical-lycl'niivalen. to si*L separate receivingl stations, all ot which rsi c.nece saril) oinfratcd. simultaneously. lli'nh a cater number oit' wavelengths a ll nio'rc complet receiving eipiipincnt a' s olf coin-scnecessary. Those skilled in the maiiinilillaion of radio receivin;apparatus will reafclili' eppri-.ciatc the practical dillicnlig, involvcd in tho operation of: such receiving equipment.

' 1t is accorl'lingjly the prii'ieipai object of the 4'presaiitinvention to provide an ellic-ient secret signaling sy in, and moreespecially a secret radio signaling s: \'stcin, which is cmnparatirelysim-ple .in structure and 1nanipulation hat h igrhlj,v effective inaccom plis-hing secret connminication.

In pursuanceof the iorogoing object 'a further object to provide meanswhereby niclzhanisn'is at two or more distantli1 separated stationswhich are not ii'iterconnected lnecllaiiically or electrically can be.operated and maintained in substantially exact syn- The inventionresides, generically, in the. utilization of gyroscopcs or other equil'aient mechanisms which are responsive in operation to thc roi ation ofthe earth for inain.- taining;` synchronizing' mechanisms or the like insynchronoiiis cooperation.

More specifically the principal. feature of the inycntirm consists inthe provision of gyreseopically-controlh-d periodically changingsignaling devices: at each of two or more signaling stations as, lforinstance, .radio sta'iic'ins.V nla-relij' the. several#stations aremaintained in syiwhronous cooperativo relie tion and whereby sei-,retcommunication may be maintained between the stations.

Asapplicd lo secret radio cmnmunication, the invention in its preferredembodiment contemplates the provision-at distantly scparatedtransmittingv and receiving stations of switching or other means f orperiod ally changing' the operating Wave length and 131 lll() exactsynehronisin so thaiA the rcceiuirg s'- f tion is able tounintermptedj.-v receive in coming si nals on periodically changing 10'stantly maintain its axis ofrotation parallel to vany plane in'space in'which 4it may be Wave lengt 'is from the transmitting station.

,It is a 'Well-known phenomenon that a gyroscope having two axes oirotation at right angles, if properly positioned with relationto theaxis of rotation of 'the' eartli, will, in effect, make exactly onerevolution in twenty-four hours aboutl one of. its axes.` rlfhisphenomenon is due to the fact that the gyroscope rotor when rotatingtends to conwhen set in rotation, While thcrotation'of `the earthcarriesthe su' porting structure of 15 the gyroscope complete y around one ofits axes once in the course of a complete revolu tion of the earth, or,in other. Words, once in twenty-four hours.. This slow rotation of thegyroscope about what will, for, convenience, be termed the secondaryaxis, is then -a function ofthev earths rotation, and is at the samerate. of speed irrespective .0f the place where the gyroscope maybelocated.- 1 The present invention utilizes this gyruscopic phenomenonfor controlling the opera- `tion. 'of duplicate Wave length changingswitches at the .transmittin and receiving stations 1n such u waythat te tuning of the l receiving apparatus is changed periodically insubstantially exact Wnchronism with the 'periodic changesf-ofA operatingjwave length `at the transmitting station.

Another feature of the invention' relates to -the means employed forIinitially synchronizingthe receivingstation with the transmitting.station. This consists of` an arrange-v ment at the transmittiiwrstation for periodicallygitrransmitting a liaracteristic tuning signalland' an arrangement attlie receiving station' for. locally duplicatingthe tuning signal or signals-in duration. and period,

butpreferably, not in tone. Both 'the incoming `and local tuningsignalsmay be heard at the receiving station when thetwo stations-.are notsynchronized, but the ai'- rangement is suchthat 1when the two stationsare synchronized the incoming and local tunjing signals 5ol tion isbrought about through the medium therefore not capable of beingdistinguished from one another. -This initial synchronizaof4 anadjustable contacter forming a part of the wave ,lengthv changing switchat the re-` ceiving station.

, The invention is not limited in its utility to vradio si fellingsystems, but is equallyl useful in ot er ty' es of signaling systems as,for instance, 1n t e multiplex printing telegraph art, wherein 'aplurality of messages are transmitted over a line simultaneously, end inwhich systems the transmitting and receiving stations are, at present,maintained in synchronism by means of tuning forks.

The preferred embodiment ot the invention as applied in secret radio'signaling occur simultaneously and are i system is described in detailhereinafter and illustrated in the accompanying drawings Which form apart of this specification.

lith reference to the drawings,

Fig. 1 is a circuit diagram of a radio telcphone transmitter inaccordance with the invention;

Fig. 2 is a circuit diagram of a radio telephone receiver `which isadapted to cooperate with the transmitter oi Fig. 1; and

Fig. 3 is a side elevation partly in cross section of a switchingmechanism including a gyroscope adapted for periodically chang'- ing theoperative wave length` at both the transmitter and receiver.

The transmitting station of Fig. 4l comprises an antenna ground circuit1 including a loading -inductance coil 2, a generator of undampedoscillations A, and-a continuously 4operable Wave length changing switchB.

ment, a grid and a plate.- A. battery 5 supplies current through therheostat 6 for heating the filaments of both tubes, and a direct currentgenerator 7 is connected in the lilament-plate circuit for supplyingspace current to the tubes. A choke coil' 8 is inserted in thcfilament-plate circuit for smoothing out irregularities in thecurrent-from the generator 7. Condenser 9 functions as a bypass for highfrequency currents in the lilament-plate circuit. The inductance coil 2is common to both the filament-plate circuit. land 'the filament-gridcircuit, and operates as a feed-back connection whereby the circuit isrendered oscillatory. The func-tion of thegrid condenser 10 is tonegatively bias the potential of the grid.; and grid leak resistance 1loperates to prevent the accumulation of an excessive potential on thegrid.

An interrupter -or ehoigipei` 12 is inserted in the grid conductor 10,but is normally" shunted oy switchl. The interrupter l2 is designed tointerrupt the gridcircuit at a suitable tone frequency. for thepurpose.cfs transmitting audible tuning signals, as'will be referred tohereinafter.

The Wave length changing svvitch B,

shown schematically inpFg. 1 and in oonl y siderable detail in Fig. 3,comprises a coniii'iutator 14,hav1ng, 1n this instance, nine insulatedmetal segments S, to S, inclusive, and three smaller segments T1, T2 andT8, which may be conveniently referred to as. timing segments. v

Referring to Fig. 3, the commutator 14 is rigidly scoured to shaft 15,to which is also secured a pinion 16. Shaft 15 is driven by gear 17through the medium of the inter-l mediate gear 18 and pinion 19. Asuitable gear speed ratio between gear 1'? and pinion 19 and likewisebetween gear 18 and pinion 16 is lzO, and the resultant ratio betweenmounted on sha:

mames gear l and pinion 1 6 is 1:1600. Gear 17 is riginflly Secured toSiria-.lit 20, which is lJoiecl at its eii'il to 'form a ibeaiing for'shaft l5 which is joui-nalecl therein.

Ten metallic. eoliecfos 'sings 21am shown l5. These are., of course,`insulated from each other and 'from ilie shaft Each 'ofnine of iliesecollecte? rings is individually coriiiele jo a segment 51, S2, etc., andthe remaining colleetoi" is conneoteci to the timing; segments TM and Tain parallel. These connections are noli showmvbut -itwill beunderelioocl that suitable conflueoi's for this puifpose may liereadily'provided, Y

Shaft 2O is jourcnalecl iii llieaiing and is secured yco the rotor ying,Q3 ofc' the gymscope. Shaft and the bearing .Qtizfl 24. which isjoul'naledl iii beafiiig; 5./ are coax 'with what was .referred tolieireinbeloire :is

the secondary axis of rotation e. the

.,i'ies the yolci.

ence letters A pair of electric moioi'hA amil 27 llave 'their armaturesmounted on a Shall, 128, mi which .is also mounted the gyroscope rotor*2i). Shaft 28 is .iouiiialofl in bearings 3() aiiil 31, forming a peiloli the ioioi ling 23. ffl pair of collectoi xrings 54: are iiio'vided:for effecting electrical' oon'neolioi'ia io the motors 26 and 27.

The entire mechanism. of the gljyioscope angl wave length changing'svi'iieli so fai" ,desoribed is carried 'by the seiii,ioiieulaii yokeWl'iicll in. turn is mounted. om lio peiosial and is aiigulai'lyailiusiiabie thereon. as may be iifilelieil from the Calilii'ajo rm lieyoke.

lfm .fffs-.ordanoe with one of tiie Well-i nown .lali's governing theaction of @woei-oyes, ilio irolor 59, when iotalpiiig it u.froiieilei'able vomi. wiil teiii :flnorigl'y llo iiiaiiilaiii its axis;of rotation iiaiallel to any p 11C AL12 which it may liaii'p i to beiiiitialli7 il. H theo the s l; il

tely

iii-,e mi; "plane wl ie ilio ifa 2 ami,

iii

iitii'o pia* n olea ei a oi pa L .i iis action oi? die gyra scope,bomma-'eig tool; @ppal iii, lo 'lliif oli serrer, auf? for all Liaeioalpurposes; il; :mav be said fhalz the ring QB rotates about tile axisR---R once 'for each revoliiti of itl e earth. ll- 'ifolloi fear r 'lienthat einem a 1v1-tio oi 1.1.1600 interposed between tlm Condoom rotoriiiiggj t2?) and 'the ooiiiiuiitzator 145 the latter wi l rotaie ai the.rate o'E 1.600 revolu- Lions in wrenty-:loui hooi-s or 1.111. R. P. M.,and since libe vommiitatoi' iii this instance is provided with ninesegments, there will be SlXljllzQQQ, oir approximately ten wave lengthchanges pei' minute.

On Liuc-omit of the gear ratio employefl, a Ivory consicloifalile torqueis regioire-o of eoiigiiieiable proportions would be requiifeal toSupply auch :i torque. in oitfiei 'to malte it possible to 'utilize arelatively small gyroscopo, it is Lnopoeo to Lise an auxiliaiy drivingmotor as, loi.l instance, a Spi-ing' i'iioiioi' 3&1-, which engages gear17 through inlie meifliiiii oi' pinion 35. The ai'ixiliaiy iiiolif, "li5 piel'eifabl-v designed lo ssp'ily eiioxgli iioi'celo l'lie L ,iii .lTto bnl ance llio md eo i-iial; l'flie gyioscopeiias prac 'lziizally nomari to oai-ry Time the size olf tio.: g iroscoiie may lie ieiilui-eiito a minimum and. ite function iiiia'y 'oe ibstaiitially that of i;"oi'oiiioi only. W iii@ lliv auxiliary Iiioloif lY ver); desirable, itdoor! not' emiiiiveiitioi'i.

oiilao. wiper arm is insulativel); mired to lle f fieeve 37', Wliii'rliis bored to oeife il righi, iiaiizl emi opii' il?, l5. iailei v videdwith knob 31'" whereby the Contact Wiper ajiii'x 3G may be iiialiiiallyrotated velaiive lo the commutator Exif. `This provision im' afljiieiiog'Elije ooii'tiwl; ii'ii'iei" ai'iii is use l'iil i'iioi'i; particularlyat llie receiving A:#iatioii for' e-:liieetiiig ixiiiial symzlioniem.but if, muy also lie employed to gooii aclvaiiage ai; the ti: JmittingStation,A aitliough 'it isi not inilihiiensalile there.

llel'ei'x'ing again izo Figli. 1 ilse infinis-:mitiiiiisl' wow.: lengthalia'ogc are ullwflml by wrioclic'ally iwiijving lli@ i'ezirr'lai'1r :eol lie zu teiiizi g'oiii'icl Gironi imrl l`oi lliie piiiposo is 3Q to l?iiioliisivo ol? (lii'i'ei'ml, oa'paritios may be f'ein'eiiivntlyutilized. lim-li ol {lieu-se minions i:` corina-uuml iliii-,iiggjli .iiillude oi'. so'ilili ibi izo ai. ooiiimiiln im' zvi'giiwiii. lTiH i..Fit, ilrqiioiii'i'lji'. lliewo voiiiim'limis laying' malle 'tlwoiiglitlw in liiiiii o1' Lei)ii'uponiliiig ooiloiloi' i'ii f-: il .3) :milsuitable lii'ii.-:lu ii'liicli :1ro noi; shown. nmiiluciioi' lll)esiablislxos a venom-lion lieiii'wii Contact wiper arm fil' :imiindocmim son '1.5. li Lilo invention im :.i'iiiiifril to miliotelephony, any :iiiiialile iiioiliilziloi' oi' system. of modulation as,lm' iiislanieT a magnetic iiioiliilriloi' 5l), may im iofai mi in theLimoni` inail ol? ifi@ antenna ground circuit ovgelliei' with aiiiioifopl'ioiie 5l, which would ordinarily lie provided inci'mjuiiction tliei'eWi-tli.

l `i-om the foregoing description it will be quite readilyundeisioodtlmt in .opel-ation iiw con'iiiiutatoi lai. is i'olatinp; at.a uniform spinal miller the Coni-'ol oi" the gyroscope and to turn theshall.; 2li. zuid a gyioscope i i; jouilialefl therein, amil is pifo-.

Therefore,

that one end of the contact wiper arm engages the segments S1, S2, etc.,successively,

thereby connecting the condensers '39 to 4:7 in seriatiin, andaccordingly changing the operating wave lengt-h periodically. In normaloperation switches-48 and 13 are set in the positions shown.

It is, however,- necessary to initially synchronize the receivingstation with the transmitter, and for this purpose the thi-ee tuningsegments T1,'T2 and T3 are provided. These timing segments may beconnected into the antenna ground circuit in series with condenser 53 bythrowing switch 4.8 into a position wherein switch blade 52 engages itsfixed Contact. With switch 48 thusthrown into its off-normal position,it will be seen that for each revolution oi' thecoinniutator, threeimpulses are transmitted into the ether, one 'for each segment T T2 andT3. If switch 13 is open, the high frequency Waves constituting each ofthese three inipulses are chopped into audible frequency groups, as issometimes done in the case of undainped wave tclegraphy.

The reccivingstation shown schematically in Fig. 2 includes atuningswitch C, which may be structurally the same as the wave lno anyother suitable type, as willbe readily apparent. vThe antenna groundcircuit .includes a vari-able'inductance coil 56, and:

may' include a second lcoil 57 which functions in connection with thcoperation of initially synchronizing the receiving station with thetransmitter. The tunin of this receiving circuit in accordance with thepe riodic chan es of wave lengths' transmitted isaccoinplis ed byconnecting condensers 58 t0 66 inclusive, in seriatim, 'in parallel withthe inductance coil 56.

Each of the last-mentioned condensers is connected through a blade ofswitch 68 to one of the segments S1, S2, etc., and it will be readilyapparent from an examination of the circuit that each/'ot theseeondensers is brought into operation when'its correspond ing segment isengaged by the contact wiper arm 69'. The capacity of condenser 70 iasuitable fortuning the circuit ior the recep.i l

tion of the previously-inentioned tuning signals, 1n order to receivethese sifmals, switch 68 is thrown out of the normal position in whichit is shown into its oiinornial position, wherein switch blade 7lengages its fixed' contact and whereby condenser Z0 is connected incircuit. `The' periodic tuning signals from the transmitting station maythen be heard in the telephone 72. For the purpose ot synchronizing thetuning switch C with the wave length changing switch D at thetransmitting station, an auxiliary buzzer circuit E is provided at thereceivingA station. This comprises a buzzer 7B having an audible tonefrequency, a suitable inducta'nce coil T4 in inductive relation to thecoil 57, a. condenser 75, and a battery or other source ot current 76. Aswitch '77 is provided for closing the buzzer circuit.

With the latter switch closed, the buzzer.

circuit is extended to the tuning segments T1, T2, T3, and thencethrough the contact wiper arm, and is closed each time the contact wiperarni engages one of the tuning segments. Since there are threetuningscgniente, the buzzer 'Filis operated three times in successionfor each revolution oi' the conimutator i4. lt will now be quite'readily apparent that it' the wave length, changing switch B at thetransmitter and the tuning switch C at the receiver arc notsynchronized, both the incoming tuning signals and the locally generatedtuning signals which are set u i by the buzzer 73 will oe heard in thetelephone 7 2. By turning the knob 537 (sec-Fig. the contact wiper anni69 at the receiving station may be rotated until the local tuningsignals and tbeinccming tuning signals are exactly blended. lNhen thusada justed, the two stations will be. in. substantiallycxactsynclironisin, and the 68 and 77 at the receiving .static-n and switchesd8 and 13 a't the tienen)ittng` staf The detector circuit D comprises athree l element vacuum tube 7 8, a. ilanient battery 7 9, afilament-plate circuit battery 80, a grid condenser 81, a grid leakresistance 82, and a ticklcr coil 8B. This is a simple circuit of thewell-known regenerative type, and it is thought that its operation willrequire no explanation.

An attempt has been made herein to iilustrate and describe thisinvention in its sini` plest terms. It will no doubt be recognized bythose skilled in the art that in practice it might be'expedient toelaborate somewhat upon the circuitl shown. For instance, it will bereadily ,recognized 'that more than one adjustment might be desirable atboth the transmitter and receiver. This would probably require one ormore additional. commutatore and associated contact wiper arms on theshaft 15 ateach station. Furthermore, the receiving station would in allprobability be iprovided with vtwo or more stages of ampli "cation,

Means other than gyroscopes which are capable ot utilizing therotational eii'ect of the earth for the purpose of maintainingsynchronism as, for instance, a pendulum, are considered Yfor thepurpose of this invention as being' equivalent tc a gyroscope.

Many modifications oi' the present inven tion will be readily.apparentto those skilled switches enemy,

nwaees in the art, and itis not desired that the in vention be construedas limited except byV cluding a gyroscope for mutually synchronizingVthe operation oi -aid transmitting and receiving apparatus.

2., In a signaling system, signal transmit tino' apparatus, and agyroscope 'for conA trolling the operation of said transmittingapparatus.

3. `In a signaling system, receiving appa ratus, and a gyroscope forcontrolling the 4operation of said receiving apparatus.

4. In a signaling system, signaling appa 'ratus, and means forperiodically changing; the 4operating characteristics of said apparatus.said means including a gyroscope.

5. In a signaling system, a high frequency transmitting station havingmeans .for periodically changing its operating frea high frequencyreceiving station for cooperating with said transmitting station havingmeans for periodically changing 'its operating frequency, and meanscontrolled by the rotation of the earth :for syn' chronizing theoperation of said first and second means.

6. In a signaling system, a transmitting station, a receiving station,and means controlled by the rotation of the earth tor maintaining saidstations in communicative relation toeach other.

7. In a vi'ave signaling system, a high frequency transmitting station,a high frequency receiving station, means atgeach of said stations forperiodically changing their respective operating frequencies, means forinitially syncl1ronizing.,said receiving station with said transmittingstation, and 'means responsive to the rotation of the earth forcontrolling both of said first-mentioned `means whereby said stationsare maintained in synchronism. y

8.A In a wave signaling system, a high tre` fluency station, means torvperiodically' changing the operating frequency ofsaid station, andmeans responsive tothe rotation of the earth for controliing theoperation et said first means.

9. In a signaling system, a transmitting station, a receiving station,said stations being adapted 1o cooperate only when one is operativelyadiusted with respect to the other. moans ior continuously Varying theoperative adjustment ofsaid stations, and controlling means for saidfirst `means whereby said -stations may be' continuously maintained incooperative adjustment.

10, In combination with 4signaling apparatos, means operable forcontrolling the operation of said signaling apparatus in a predeterminedmanner, and means responsive to the rotation of the earth formaintaining the operation of said lirst means at a uniform time rate.

11. In combination with signaling appa ratas, means operable'torcontrolling the operation ol said signaling apparatus in a.predetermined manner, and means including a gyrosoope t'or maintainingthe operation of said first means at a unitorm time rate.

.l2 In combination with signaling apparal-vus, means operable for4controlllng the operation ot said signaling apparatus in a predeterminedmanner, and means respon sive to the rotation oi' the earth forcontrolling the operation of said firstmeans in accordance with apredetermined time factor.

13. In a signaling system, signal propagating means, means for changingthe character ot the propagated signals in accord ance with apredetermined time factor, and means responsive to the rotation of theearth for controlling said nrst means in accordance with said timefactor.

14.` In signaling system, signal prepa" gating means, means for changingthe character ot the propagated signals in accordance with apredetermined time tactor,'and" means including a gyroscope forcontrolling said i'irst means in accordance with said time factor.

15. In a signaling system, high frequency signal propagating means,means for chang ing the frequency of the propagated Signals inaccordance with a redetermined time factor, and means inclu inggyroscope for controlling said irst mesns'in accordance with said timefactor.

16. In a signaling system, a plurality ot high frequency stations, meansfor periodically varying the operating frequency of said siations, andmeans responsive to the rotation of the earth for synchronizing theperiodic variations o said stations.

17. In a signaling system, a transmitting station having means forgenerating and. transmitting signaling Waves of a plurality offrequencies, a switching mechanism at said v'transmitting station .torperiodically changing the frequency of the signaling ULJ KBRVKH Waves, areceiving station having means for receiving and indicating thesignaling waves from said transmitting station, a switch mechanism 'atsaid receiving station `tor periodically changing the tuningvof saidreceiving means, said switching mechanisms IBUVIUI Waves, a receivingstation havingr means for Lib i receiving and indicating the signalingwares from said transmitting station, a switching mechanism at saidreceiving station for periodically changing the timing oit said.receiving means, said switching mechanism when operated in' synchronisiubeing adapted to maintain said stationsin communicative adjustment, andmeans including a gyroscope at each of said stations Jfor maintainingsaid switching mechanisms in syn-- clironisin.

19. In a signaling system, a transmitting station having means forgenerating and transmitting signaling ivaves of a plurality offrequencies, means for periodically changing the frequency of thesignaling receiving and indicating signaling waves from saidtransmitting station, means for periodically changing thetuning of saidrer ceiving station in accordance with the :tre-

quency changes ot' the signaling Waves transmitted from saidtransmitting station, means'atv said transmitting station fortransmitting a timing signal, and iiieans at said receiving station foradjustiinf. in vaccordance with said tuning signal, said means forperiodicallyr changing the tuning' of said receiving station.

20. In a signaling system, a high 'frequency transmittingr station,means continuously operable during the operation ci said transmittingstation for periodically changing the frequency of the transmittedsignals, a receiving station comprising high frequency signal receiving1apparatus, means continuously operable during` the operation ol' saidreceiving station for periodically changing the tuning of said receivinganparatus whereby said receiving' station may he 'maintained inopt-iatirc synchiouisin with said ti'ansn'iitting station, means at saidtransmittingr station for tansniitting a characteristic tuning signal atregular interv is. and means at said receiving' station forsynchronizing said second-nicntioncd means with said first-nientiouedmeans, sail s vn hroniziiig means being oncrahlc in con-- jun'rtion withsaid tuningl sgi'nn'l.

1. ln a signaling system. a high frequencytransmitting stationcomprising s :reir er Ator ot high frequency cogitinuouslv 'ioei'ahleiici'iiuuntion. switch1 ciyrcuit connections between said generator andsaid permutation switch wherein' said switch is adapted lo inriodicnllvchange the ope atingfrequency ol said generator; and means responsivelto the rot ation ot the o'ai'th for maintaining thc oi'ierntion oi' saidierinutation switch suhstantially constant..

In u signaling system, a high frequensigi'ialing naves` a` cyltransmitting station comprising a generator ot high frequency signaling`wares, a continuously opcahle pcrn'iutation switch, -circuit connectionsbetween said generator and said pernuitation switch whereov said switchis adapted to periodically change the operating frequency of saidgenerator, and means incliuling a ri'yroscogie ,For maintain ing' theoperation of said pei-imitation switch substantially constant.

The ci'iinhination with a continuously movable switching device of meansincluding a gyroscope :tor maintaining said device in operation atconstant speed.

2li. The combination with a continuously movable switching device of agyroscope having a major axis of rotation and a secondary airis ofrotation, and ineens responsive to the. rotation oit said gyroscope onsaid secondary axis oi", rotation 'for maintaining said switchingdevicein operation at constant speed.

25. In coufihiiuition` a switching mechanism having a fixed contactingnicinlier and a movable contacting niemlier. a gyiosconc so disposedwith. respect to the axis ot the earth that it will rotate on one of irelatively to the earth at a uniform snee L ndeiit upon 'the rotationont the earth. and means for utilizing said rotation oi' the, gyroscopefor imparting a uniform increment to said nio 'able contat'tine`inen'xher.

2G. in a s` 'naling system. a high frequency transmitting stationcomprising ineens for generating high lrequerny signaling Waves. a'permutation switch nt said transmitting station for periodically'changing the oiieiatini iiequeiu-y' ot said generating means, saidswitch including; moans' ed for transmitting; cha, tic. tunic nais atregular pradet rnaiiieti interi/:i receiving station comprising." meansttor res ceiving and indicatfuo; the sigiuilh" from said transmittingslzitimi. a. permutation switch at said i' cciri station forperiodically changing the timing at the receiviiinT incaus tl'ui'cut insynchronisin with the changes in operating frequency' at saidtransiniitiiul station. said inst-inentioncll 'permutation switchincluding nicaiis for in.- ilicnting' synriiionisin 7oetween sait-l.steth-un in accordance with said tnniuii ouais.

2T in n. Hiszualiuyu retenu n hugh 'i'eoinuci' transmitting station. :ihigh ircigiieucy rcceiring statioin :i .wuitiuuously movable switchingmechanism at said transmitting station for periodical-li changing theoperatingl frequency thereof. a continuously mov- :ihle switchingmechanism at said receiving station for periodically changing thetuning` ion,

llt)

oit receiving' station in sliiichronisniI acteriste tuning Signals atregular prede termined interves eensolmnt with the periedc frequencychanges at seid txansmi.- ting station, e local souree of tuning;signals comprising a circuit and source of eurrenf4 at seid receivingstation, seid swichng mer ml nism ai; Said receiving staton beingoperable to close the circuit of said oea source 'et predeterminedintervals and durations eer responding with the intervals and durationsef the transmitter' tuning signals, means for adjusting the switchingmechanism at' seid 'receiving station for efeetng initial symA Intestimony whereof 'we e'x 'mu' signa? tures.

LYNDEN v l IVMLTLJCULM l. PARKEHJRS'.

